Acid-Spraying, Lobster-Like Arachnids Emerge in Texas to Look for Love

Summer rains send vinegaroons scurrying from their burrows in the desert

A vinegaroon faces the camera with its pincers raised in the air
Vinegaroons spray acetic acid—the substance that gives vinegar its pungent scent—from their tails. Laura Gooch via Flickr under CC BY-NC-SA 2.0

In the West Texas desert, summer rains usually cause wildflowers to sprout and cacti blooms to burst forth.

They also result in the emergence of “land lobsters from hell,” reports Abigail Rosenthal of the Houston Chronicle. More commonly known as vinegaroons, this unusual creature isn’t a actually crustacean—it’s an arachnid. The eight-legged critter has a nasty bite and sprays a vinegar-like acid from its tail. According to a Big Bend National Park Facebook post, summer rains bring the amorous arachnids out of their burrows in search of love and food.

Found in Texas, Arizona and Florida, the creature sprays attackers with a solution of 85 percent acetic acid to protect themselves. It may also pinch a finger that gets too close, reports Jenna Romaine of Changing America.

“They can pinch with their heavy mouthparts (pedipalps),” according to the Big Bend National Park Facebook post.

Vinegaroons have a long whip tail at the base of their abdomens. The arachnids are often called “whipscorpions,” though they are not related to scorpions and don’t have stingers.

According to the American Museum of Natural History, the vinegaroon in North America is actually seven different species. Recent research reveals more variety in this creature, which can be found in tropic locations around the world.

“It’s amazing to find a seven-fold increase in the diversity of an entire arachnid order in North America,” writes Lorenzo Prendini, a curator at the museum’s Division of Invertebrate Zoology and a co-author of a 2018 paper about the assortment of the species in this part of the world.

According to Texas A&M AgriLife Extension, vinegaroons are not poisonous to humans, reports Mary Claire Patterson of KSAT TV. However, they can leave a mark because of their large pincers they use to capture other insects.

Texas A&M recommends letting the arachnids live since they eat other bugs like millipedes, scorpions, crickets and cockroaches. Big Bend National Park officials report vinegaroons hunt by sensing the vibrations of prey with their long front legs.

Since they generally come out after dark, it is rare to see a vinegaroon in the daylight. If you should happen to stumble upon one, Big Bend's Facebook post advises checking it out: “If you’re lucky enough to see one, look closely. If it’s a female, she may be carrying her hatchlings on her back.”

Editor’s Note, July 28, 2021: A previous version of this article incorrectly stated that arachnids are insects, when, in fact they belong to two separate classes: Insecta and Arachnida. The story has been edited to correct that fact.